How can I use the ST-E2 wireless transmitter as an infrared light aid for AF?
The ST-E2 can be attached to the D30 for triggering external flashes (like the 550ex and 420ex) and also as a AF aid for the camera. When attaching the transmitter, the camera will operate the exact same way as if a flash is attached. Because the transmitter has no flash, it exposes entirely to the ambient light and uses the camera’s metering the same way it would if a flash was being used. Also, if you are using the custom function 2-1, you will loose the ability to lock the exposure when pressing the shutter button halfway. The side effect of this, is that when reframing your shots, the exposure may be off. A workaround is to use custom function 2-0 and use FEL to lock exposure when using the transmitter.
